Batch processing and error handling in CSV upload in Rails - ruby-on-rails

Question

I am using active admin and uploading the records into the database from CSV file. However, there are two issues occurs here; Code breaks if any filed is missing and secondly performance is very week, can't we do it in the batch process. It is an important and I believe many developers thinking a good solution for such problem.
require 'CSV'
class CsvDb
class << self
def convert_save(model_name, csv_data, field_name=nil)
target_model = model_name.classify.constantize
csv_file = csv_data.read
row_headers={}
counter=0;
#Thread.new do
CSV.parse(csv_file) do |row|
if counter==0
temp=row
row_headers = Hash[temp.map.with_index.to_a]
counter +=1
next
end
unless row[row_headers["name"]].nil?
temp={}
business_type = row[row_headers["business_type_id"]]
business_type_id = business_type=='Online' ? 1: business_type=='Local' ? 2: 3
temp[:business_type_id] = business_type_id
temp[:user_id] = row[row_headers["user_id"]]
temp[:name] = row[row_headers["name"]]
temp[:country_id] = row[row_headers["country_id"]]
temp[:homepage] = row[row_headers["homepage"]] ||=""
temp[:telephone] = row[row_headers["telephone"]] ||=""
temp[:email] = row[row_headers["email"]] ||=""
temp[:address] = row[row_headers["address"]] ||=""
temp[:latitude] = row[row_headers["latitude"]]
temp[:longitude] = row[row_headers["longitude"]]
temp[:facebook] = row[row_headers["facebook"]] ||=""
temp[:twitter] = row[row_headers["twitter"]] ||=""
temp[:google] = row[row_headers["google"]] ||=""
temp[:instagram] = row[row_headers["instagram"]] ||=""
temp[:pinterest] = row[row_headers["pinterest"]] ||=""
temp[:free_shipping] = row[row_headers["free_shipping"]]
temp[:ship_details] = row[row_headers["ship_details"]] ||=""
temp[:category_ids] = [row[row_headers["category_ids"]]]
temp[:style_ids] = [row[row_headers["style_ids"]]]
temp[:shipping_country_ids] = [row[row_headers["shipping_country_ids"]]]
temp[:filter_ids] = [row[row_headers["filter_ids"]]]
business = target_model.new(temp)
business.save
end
end
ActiveRecord::Base.connection.close
end
#end
end
end

Answer 1

I'll just focus on the translation of the CSV rows into an object. There's just to much repetition in the unless body. All those rows should be mentioned once, then handled in a loop instead of hard coding them like this. E.g.
unless row[row_headers["name"]].nil?
temp={}
business_type = row[row_headers["business_type_id"]]
business_type_id = business_type == "Online" ? 1: business_type == "Local" ? 2 : 3
temp[:business_type_id] = business_type_id
for name in [:user_id, :name, :country_id, :latitude, :longitude, :free_shipping, :category_ids, :style_ids, :shipping_country_ids]
temp[name] = row[row_headers[name.to_s]]
end
for name in [:homepage, :telephone, :email, :address, :facebook, :twitter, :google, :instagram, :pinterest, :ship_details]
temp[name] = row[row_headers[name.to_s]] ||= ""
end
business = target_model.new(temp)
business.save
end
Alternate solution received from code review site:
CSV.parse(csv_file, {headers: true, header_converters: :symbol}) do |row|
business_type_id = case row[:business_type_id]
when 'Online' then 1
when 'Local' then 2
else 3
end
target_model.new( {business_type_id: business_type_id} + extract_required_fields(row) + extract_optionals_fiels(row) )
.save()
end
def extract_required_fields(row)
[:user_id, :name, :country_id, :free_shipping, :category_ids, :style_ids, :shipping_country_ids]
.reduce({}) do |carry, item|
carry[item] = row[item]
end
end
def extract_optionals_fiels(row)
[:homepage, :telephone, :email, :address, :facebook, :twitter, :google, :instagram, :pinterest, :ship_details]
.reduce({}) do |carry, item|
carry[item] = row[item] ||= ''
end
end